Spatial Economic–Hydroecological Modelling and Evaluation of Land Use Impacts in the Vecht Wetlands Area

Wetlands provide many important goods and services to human societies, and generate nonuse values as well. Wetlands are also very sensitive ecosystems that are subject to much stress from human activities. Reducing the stress on wetlands requires a spatial matching between physical planning, hydrological and ecological processes, and economic activities. Spatially integrated modelling and evaluation can support this. The present study has developed a triple layer model that integrates information and concepts from social and natural sciences to address the analysis and evaluation of land-use scenarios for a wetlands area in the Netherlands, the Vecht area. This is the floodplain of river Vecht, located in the centre of the Netherlands. The study has resulted in a set of linked spatial hydrological, ecological and economic models, formulated at the level of grids and polders. The main activities incorporated in the system of models are housing, infrastructure, agriculture, recreation and nature conservation. The formulation of alternative development scenarios is dominated by land use and land cover options that are consistent with the stimulation of agriculture, nature or recreation. Two aggregate performance indicators have been constructed from model output, namely net present value of changes and environmental quality. The spatial characteristics of these indicators are retained in a spatial evaluation that ranks scenarios.     

An Assessment of the Effects of Crude Oil Pollution on Soil Properties, Germination and Growth of Maize (Zea Mays) using Two Crude Types – Forcados Light and Escravos Light

The effect of crude oil pollution on soil properties, germination and height of maize (Zea mays) was investigated under natural environment in three separate pot experiments. Two crude oil types--Forcados light and Escravos light were used. In Experiment 1, the effect of crude oil application on germination using high pollution levels of 5, 15, 25 and 40 mL kg(-1) of soil was assessed. In Experiment 2, the effect of crude oil application on maize plant height using the same pollution levels was assessed. The last experiment (Experiment 3) was used to test for the effects of crude oil application on maize plant height using lower levels of pollution (1.0, 1.5, 2.0 and 2.5 mL kg(-1) of soil). Soil samples were collected before, during and after the experiment and analyzed for some physical and chemical properties. Results obtained showed variation in chemical properties of soil. % organic matter increased from 1.34 to 2.62% in polluted soils. Available P decreased from 15.00 ppm in control to between 7.34 and 5.42 in soils polluted with 'high' levels of crude oil. Statistical analysis of height data showed that crude oil inhibited the growth of maize at high pollution levels. High levels of pollution also inhibited germination and for Escravos light there was no germination at 40 mL kg(-1) soil level of crude oil pollution.     

Can Basin Land Use Effects on Physical Characteristics of Streams Be Determined at Broad Geographic Scales?

The environmental setting (e.g., climate, topography, geology) and land use affect stream physical characteristics singly and cumulatively. At broad geographic scales, we determined the importance of environmental setting and land use in explaining variation in stream physical characteristics. We hypothesized that as the spatial scale decreased from national to regional, land use would explain more of the variation in stream physical characteristics because environmental settings become more homogeneous. At a national scale, stepwise linear regression indicated that environmental setting was more important in explaining variability in stream physical characteristics. Although statistically discernible, the amount of variation explained by land use was not remarkable due to low partial correlations. At level II ecoregion spatial scales (southeastern USA plains, central USA plains, and a combination of the western Cordillera and the western interior basins and ranges), environmental setting variables were again more important predictors of stream physical characteristics, however, as the spatial scale decreased from national to regional, the portion of variability in stream physical characteristics explained by basin land use increased. Development of stream habitat indicators of land use will depend upon an understanding of relations between stream physical characteristics and environmental factors at multiple spatial scales. Smaller spatial scales will be necessary to reduce the confounding effects of variable environmental settings before the effects of land use can be reliably assessed.     

Effects of the homogeneous traffic on vertical dispersion parameter in the near field of roadways – A wind tunnel study

The vertical dispersion parameter of Pasquill–Gifford needs some modification in the close vicinity of urban roadways by considering the influence of traffic-induced turbulence. Wind tunnel simulation experiments have been carried out with controlled traffic parameters to evaluate traffic-induced effect on vertical dispersion parameter (σ_z) in the near field of roadways. The aerodynamic similarities in atmospheric flow, vehicles size and speeds have been considered with appropriate similarity criteria. The tracer gas experiments have been performed to evaluate σ_z in the near field of the roadways for variable traffic volumes and two approaching wind directions (i.e. 90^○ and 60^○). The results showed that the value of σ_z increased monotonically with increase in traffic volumes and becomes nearly constant at a particular downwind distance. It has also been found that the σ_z was considerably affected by approaching wind directions. Further, the comparison of experimental σ_z values for both approaching wind directions with those of Chock (1978) and Rao and Keenan (1980), showed an agreement within ±15%.     

Determination of Impact of Urbanization on Agricultural Land and Wetland Land Use in Balçovas’ Delta by Remote Sensing and GIS Technique

Because of their intense vegetation and the fact that they include areas of coastline, deltas situated in the vicinity of big cities are areas of greet attraction for people who wish to get away from in a crowded city. However, deltas, with their fertile soil and unique flora and fauna, need to be protected. In order for the use of such areas to be planned in a sustainable way by local authorities, there is a need for detailed data about these regions. In this study, the changes in land use of the Balçova Delta, which is to the immediate west of Turkey’s third largest city Izmir, from 1957 up to the present day, were investigated. In the study, using aerial photographs taken in 1957, 1976 and 1995 and an IKONOS satellite image from the year 2005, the natural and cultural characteristics of the region and changes in the coastline were determined spatially. Through this study, which aimed to reveal the characteristics of the areas of land already lost as well as the types of land use in the Balçova delta and to determine geographically the remaining areas in need of protection, local authorities were provided with the required data support. Balçova consists of flat and fertile wetland with mainly citrus-fruit orchards and flower-producing green houses. The marsh and lagoon system situated in the coastal areas of the delta provides a habitat for wild life, in particular birds. In the Balçova Delta, which provides feeding and resting for migratory birds, freshwater sources are of vital importance for fauna and flora. The settlement area, which in 1957 was 182 ha, increased 11-fold up to the year 2005 when it reached 2,141 ha. On the other hand, great losses were determined in farming land, olive groves, forest and in the marsh and lagoon system. This unsystematic and rapid urbanization occurring in the study region is not only causing the loss of important agricultural land and wetland, but also lasting water and soil pollution.     

Assessment of the redistribution of soil carbon using a new index—a case study in the Haihe River Basin,North China

Soil carbon redistribution is an important process in the terrestrial carbon cycle. This study describes a new index, soil carbon redistribution (SCR) index, that can be used to assess long-term soil carbon redistribution at a large watershed scale. The new index is based on the theoretical preconditions that soil carbon redistribution is mainly controlled by vegetation type, precipitation, topography/slope, and soil carbon concentration. The Haihe River Basin served as an example for this analysis. The SCR index was calculated, and a GIS-based map shows its spatial patterns. The results suggested that soil carbon was usually prone to being carried away from mountainous regions with natural vegetation, while it was prone to deposition in the plain and plateau regions with cultivated vegetation. The methods in the paper offer a tool that can be used to quantify the potential risk where soil carbon is prone to being carried away and deposited in a large watershed.     

Effects of Topographic Heterogeneity on Coarse Resolution Grid-Based Runoff Simulation—Assessment for Three River Basins in Peninsular Malaysia

This paper investigates the effects of topographic heterogeneity on the runoff response simulated by a 0.05 degree (approximately 5.5 km) spatial resolution distributed hydrological model for the Pahang, Kelantan, and Muda river basins (25,600, 11,900, and 4010 km², respectively) in Peninsular Malaysia. Daily simulations were carried out and assessed against observed streamflow for the period 1999–2004. Topographic structure was characterized by means of subgrid terrain slope to guide the decomposition of hydrological parameters over the model grid. The results show improved simulation skill for all three basins compared to a traditional runoff production parameterization scheme that does not take into account the subgrid topographic variability. However, other factors related to morphological heterogeneity and variability in physical terrain conditions should be considered in future work in order to characterize the hydrological heterogeneity. The present methodology may be of potential for further development of large-scale, coarse resolution grid-based hydrological models without adding structural model complexity and without affecting parameter parsimony.     

An Analogy on Assessment of Urban Air Pollution in Turkey Over the Turn of the Millennium (1992–2001)

Rapid industrialization and urbanization in Turkey, especially over the last twenty five years, has provided better living standards to its residents, but it also caused a decrease in environmental quality. In late 1970's, air quality monitoring activities were started in some major cities by individual researchers in Turkey. It was just around the 1990's that a countrywide program on continuous air pollution monitoring in major province centers and selected large towns was launched. The impact of air pollution on people depend on various factors, such as existence and magnitude of coal powered energy generation plants, type of urban heating and their efficiency, and the numbers and specifications of vehicles. In this study, current Turkish urban air quality over the turn of the Millennium (1992–2001) is studied in the light of the country's worst cities in terms of outdoor air quality, the number of upper respiratory diseases, sinusitis, bronchitis, and pneumonia cases in these provinces reported by the state medical treatment facilities in 2001. The population that is under outdoor urban air pollution hazard was computed. A comparative analysis between the provinces that use natural gas and others that use fossil fuels was also completed in order to project monetary gains if the studied provinces will transform their indoor heating and industrial operations to be run by natural gas or other cleaner energy sources. If natural gas use in air polluted urban centers could be realized in the near future, approximately 212 to 350 million US dollars per annum could to be saved just by reducing health related problems caused by outdoor air pollution.     

Assessment of effects of climate change and grazing activity on grassland yield in the Three Rivers Headwaters Region of Qinghai–Tibet Plateau, China

Inter-annual dynamics of grassland yield of the Three Rivers Headwaters Region of Qinghai–Tibet Plateau of China in 1988–2005 was analyzed using the GLO-PEM model, and the herbage supply function was evaluated. The results indicate that while grassland yield in the region showed marked inter-annual fluctuation there was a trend of increased yield over the 18 years of the study. This increase was especially marked for Alpine Desert and Alpine Steppe and in the west of the region. The inter-annual coefficient of variation of productivity increased from the east to the west of the region and from Marsh, Alpine Meadow, Alpine Steppe, Temperate Steppe to Alpine Desert grasslands. Climate change, particularly increased temperatures in the region during the study period, is suggested to be the main cause of increased grassland yield. However, reduced grazing pressure and changes to the seasonal pattern of grazing could also have influenced the grassland yield trend. These findings indicate the importance of understanding the function of the grassland ecosystems in the region and the effect of climate change on them especially in regard to their use to supply forage for animal production. Reduction of grazing pressure, especially during winter, is indicated to be critical for the restoration and sustainable use of grassland ecosystems in the region.     

Assessment of trace metal concentration in feathers of seabird (Larus dominicanus) sampled in the Florianópolis, SC, Brazilian coast

Cd, Co, Cr, Cu, Mn, Ni, Zn, and Pb were measured in feather samples of adult, subadult, and juvenile of Larus dominicanus, sampled in the Florianólis, SC, in the south of Brazil in December 2005, by flame atomic absorption spectrophotometry. The average of the distribution of Cd concentration in adult feathers (0.072 μg g^???1) was significantly different than that found in juvenile feathers (0.021 μg g^???1). Cu concentration averages were not significantly different between adults (13.30 μg g^???1), subadults (9.67 μg g^???1), and juveniles (13.76 μg g^???1). For adults and juveniles there was significant difference in feather concentrations for Cd, Co, Cr, Ni, and Pb. The distribution of Mn concentration averages in feathers differs between adults (11.36 μg g^???1) and juveniles (1.184 μg g^???1). Ni concentration averages of adults (5.92 μg g^???1) were significantly higher than those of juveniles (2.23 μg g^???1). For Pb, concentration averages were significantly higher in adults (7.53 μg g^???1) than in juveniles (1.47 μg g^???1). The concentration of Co and Cr in juvenile and subadults are statistically different when compared with the adults. In the present study, levels of Cd, Co, Cr, Mn, Ni, Zn, and Pb increased with age. The concentrations of essential trace elements in L. dominicanus were generally comparable to values reported in other studies. With non-essential metals (Cd, Pb, and Ni), in our study, L. dominicanus had lower values than those reported for their northern Atlantic counterparts.     

Assessment of enrichment factors and grain size influence on the metal distribution in riverbed sediments (Anll��ns River, NW Spain)

The metals distribution in the bed sediments of the Anllóns River was studied, with special emphasis on the evaluation of the metal distribution as a function of the granulometric fraction chosen for the analysis. Statistical significant differences between the distribution of K, Ca, Cr, Mn, As, Rb, Sr and Nb in the bulk (<2 mm) and fine fraction (<63 μm) were not found. Fe, Ni, Cu, Ga, Zr, Zn and Pb commonly appear in higher concentrations in the fine fraction, whereas Ti appears in higher concentrations in the bulk fraction. In general, it was observed that contamination phenomena tend to equalise the concentrations of both fractions, and this was mainly explained as the result of two processes. First, the formation of coatings over sands and, second, the formation of large aggregates (pseudo-sands) at sites located over basic rocks, whose chemical behaviour is closer to that of clays and could be responsible for significant adsorption processes. Normalisation techniques to evaluate contamination were applied by testing Nb, Sr, Rb or Ga as normaliser elements and by using crustal or shale average values for background concentrations. The most satisfactory result was obtained when using shale average values and Ga as the normaliser element. Arsenic was identified as the main contaminant of the basin, exceeding in all cases the low-effect reference values proposed by sediment quality guidelines and in two cases the medium-effect reference values. These sites were identified by multivariate techniques, which allow differentiating site 10 as affected by anthropogenic inputs related to past mining activities.     

Estimation of spatial distrubition of groundwater level and risky areas of seawater intrusion on the coastal region in Çarşamba Plain,Turkey, using different interpolation methods

Groundwater level plays a significant role in coastal plains. Heavy pumping and excessive use of near-coast groundwater can increase the intrusion of seawater into the aquifers. In the present study, groundwater levels were measured at 59 groundwater wells at different times during pre- and post-irrigation seasons (April and September of the year 2012) in Çar?amba Plain, Turkey. To select the best method, two deterministic interpolation methods (inverse distance weighing (IDW) with the weights of 1, 2, and 3 and radial basis function (RBF) with spline with tension (SPT) and completely regularized spline (CRS)) and two stochastic methods (ordinary kriging (OK) with spherical, exponential, and Gaussian variograms) and cokriging (COK)) were compared and then the best interpolation method was used to evaluate the spatial distribution of groundwater levels in different seasons and seasonal changes. A total of nine different techniques were tested. Also, risky areas of seawater intrusion in coastal area were determined using the best methods for two periods. The performance of these interpolation methods is evaluated by using a validation test method. Statistical indices of correlation (R ²), mean absolute error (MAE), and root-mean-square error (RMSE) were used to select and validate the best methods. Comparisons between predicted and observed values indicated RBF as the optimal method for groundwater level estimation in April and September. When the best method RBF and the worst method IDW were compared, significant differences were observed in the spatial distribution of groundwater. Results of the study also revealed that excessive groundwater withdrawals during the post-irrigation season dropped the groundwater levels up to 2.0 m in some sections. With regard to seawater intrusion, 9,103 ha of land area was determined to be highly risky and risky.     

Assessment of water quality in the Messolonghi�CEtoliko and Neochorio region (West Greece) using hydrochemical and statistical analysis methods

Assessment of the water quality can enhance understanding of the hydrochemical system and effective management of water resources. To this end, an assessment of water quality was conducted in the Messolonghi-Etoliko and Neochorio region. Surface water and groundwater samples have been collected, treated, and subjected to chemical analysis for the following parameters: Br?, Cl?, F?, NO??, NO??, PO?3?, SO?2?, Li?, Na?, NH??, K?, Mg2?, Ca2?, HCO??, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. A characterization has been carried out using the Piper trilinear diagram, the United States Salinity Laboratory diagram, and the Wilcox diagram. Assessment of water samples by comparing the recorded values of the water quality parameters with the parametric values established by European Community indicated that the 50% of the surface water samples and 67% of the groundwater samples in the study area are chemically suitable for drinking use. Assessment of water samples from calculation of chemical indexes like sodium adsorption ratio, sodium percentage, residual sodium carbonate, and by comparing the values of the water quality parameters with the water quality limits established by Canadian Council of Minister of the Environment indicated that 75% of the surface water and that all the groundwater samples are chemically suitable for irrigation use.     

Spatial Patterns and Rankings of Contaminant Concentrations in Herring Gull Eggs from 15 Sites in the Great Lakes and Connecting Channels, 1998–2002

Mean values of eight contaminants in Herring Gull (Larus argentatus) eggs were calculated for 15 Great Lakes sites for the 5 year period 1998–2002. The sites were ranked according to the concentrations of each of seven compounds relative to fish flesh criteria for the protection of piscivorous wildlife, and a single overall rank of contamination was calculated for each site. Based on this weighted ranking scheme, we found that sum PCBs, dioxin and DDE contributed the most (60.2, 30.5% and 8.5%, respectively) to the overall rankings. The weighted ranking scheme showed that eggs from Channel-Shelter Island (Saginaw Bay, Lake Huron), Strachan Island (St. Lawrence River) and Gull Island (northern Lake Michigan) ranked as the three most contaminated sites, while Agawa Rocks (eastern Lake Superior), Chantry Island (southern Lake Huron) and Port Colborne (eastern Lake Erie) ranked as the three least contaminated sites. Two of the three most contaminated sites are Areas of Concern; none of the three least contaminated sites are Areas of Concern.     

Assessment of seasonal effects of municipal sewage pollution on the water quality of an urban canal—a case study of the Buckingham canal at Kalpakkam (India): NO3, PO4, SO4, BOD, COD and DO

The seasonal effects of untreated and treated municipal sewage on the nutrients-nitrate (NO(3)), phosphate (PO(4)), sulphate (SO(4)), and the biochemical oxygen demand (BOD), chemical oxygen demand (COD) and dissolved oxygen (DO) of the receiving urban canal, the Buckingham canal at Kalpakkam (Tamil Nadu, India) was monitored monthly during pre- monsoon-2005 to post-monsoon-2006. The NO(3), PO(4) and SO(4) contents were higher in the downstream than that of the upstream of the outfall points of treated as well as untreated sewage, of the canal. The NO(3) and PO(4) contents were higher during summer than that of monsoon; however the SO(4) was higher during winter and lower during summer in the canal water. The BOD and COD were lower and DO was higher at the upstream than that of downstream of the canal. The concentrations of BOD and COD were higher during summer season, which decreased during monsoon season, while the DO decreased during the summer season and increased in monsoon season in the canal water. Cluster analysis applied to the six sampling points of the canal, has grouped them based on the water quality similarities.     

The effects of grassland degradation on plant diversity,primary productivity,and soil fertility in the alpine region of Asia’s headwaters

A 3-year survey was conducted to explore the relationships among plant composition, productivity, and soil fertility characterizing four different degradation stages of an alpine meadow in the source region of the Yangtze and Yellow Rivers, China. Results showed that plant species diversity, productivity, and soil fertility of the top 30-cm soil layer significantly declined with degradation stages of alpine meadow over the study period. The productivity of forbs significantly increased with degradation stages, and the soil potassium stock was not affected by grassland degradation. The vegetation composition gradually shifted from perennial graminoids (grasses and sedges) to annual forbs along the degradation gradient. The abrupt change of response in plant diversity, plant productivity, and soil nutrients was demonstrated after heavy grassland degradation. Moreover, degradation can indicate plant species diversity and productivity through changing soil fertility. However, the clear relationships are difficult to establish. In conclusion, degradation influenced ecosystem function and services, such as plant species diversity, productivity, and soil carbon and nitrogen stocks. Additionally, both plant species diversity and soil nutrients were important predictors in different degradation stages of alpine meadows. To this end, heavy degradation grade was shown to cause shift of plant community in alpine meadow, which provided an important basis for sustaining ecosystem function, manipulating the vegetation composition of the area and restoring the degraded alpine grassland.     

Comparative study of fluvial lakes in floodplains of the Elbe,Lužnice and Svratka Rivers based on hydrochemical and biological approach

The aim of the thesis was to specify key differences in chemistry and biota (zooplankton communities) among fluvial lakes in three regions of the Czech Republic: the central part of the Elbe River, the upper part of the Lu?nice River and the upper part of the Svratka River. The ten studied lakes of the three regions differ in size, geology, shading, connection with the river and the level of anthropogenic impact. The following hypotheses were tested: (1) The water chemistry of fluvial lakes significantly differs in different floodplains. In the central Elbe River floodplain, there are the highest values of conductivity and concentrations of organic matter and nutrients. Fluvial lakes of the Svratka River floodplain show the lowest level of these parameters, and fluvial lakes of the upper Lu?nice River have levels intermediate between the two previous regions. (2) The chemistry of fluvial lakes that have contact with the river through surface connection is significantly influenced by the river. (3) The structure of zooplankton differs in different lakes due to the geographical distance between locations, their different altitude and water chemistry. The PCA analysis of selected parameters of the water chemistry revealed a close relationship of locations in the central Elbe River floodplain on the one side and close relationship of the locations in the upper Lu?nice River and Svratka River on the other. However, the amount of organic matter, nitrogen (with the exception of nitrates) and phosphorus was independent of the region. The relationship between the extent of the lake-river connection and the water chemistry was not significant. The hypothesis that the zooplankton differ in different lakes was not proved—the species composition was similar in all the lakes.     

Long-term trends and short-term variability of water quality in Skive Fjord, Denmark – nutrient load and mussels are the primary pressures and drivers that influence water quality

Nineteen years of monitoring data from the eutrophic Skive Fjord, Denmark were examined for linkages to external pressures and drivers, including nutrient inputs, meteorology and stocks of blue mussels. Linkages were examined by: 1) time-series analysis to document effects of nutrient reduction programs, 2) Pearson Rank correlations, 3) multivariate statistical analysis (PLS) to identify water quality variables with high predictability and their linkages to pressures, and 4) regression analysis to quantify relationships between pressures and water quality. Freshwater input, nitrogen load and phosphorus load showed decreasing trends through the period 1984–2002. The load reductions were only partially translated into trends in water quality: phosphorus decreased in most seasons, while total nitrogen decreased during winter and spring only. Phosphorus concentration had the highest predictability (explained by seasonal temperature variation) followed by transparency, silicate, tot-N, chlorophyll-a, primary productivity, phytoplankton diversity and phytoplankton turnover. The variation in pressures other than nutrient input confounded the relations between loads and water quality. High biomass of mussels led to reduced chlorophyll-a and increased transparency, while short-term variability in water column mixing led to changes in chlorophyll-a due to nutrient entrainment and coupling to benthic mussels.